Amphiphilic macromolecule and the purpose of this amphiphilic macromolecule

ABSTRACT

Amphiphilic macromolecules having structural units to adjust molecular weight and molecular weight distribution and charging property effects, high stereo-hindrance structural units, and having amphiphilic structural units. The Amphiphilic macromolecules are suitable for fields such as oil field well drilling, well cementation fracturing, oil gathering and transfer, sewage treatment, sludge treatment and papermaking, etc., and can be used as an oil-displacing agent for enhanced oil production, a heavy oil viscosity reducer, a fracturing fluid, a clay stabilizing agent, a sewage treatment agent, a papermaking retention and drainage aid or a reinforcing agent, etc.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a national stage entry of PCT/CN2011/001578 filed Sep. 16, 2011, which claims priority to Chinese Patent Application No. 201110210344.1, filed on Jul. 26, 2011, said applications are expressly incorporated herein in their entirety.

TECHNICAL FIELD

This invention relates to an amphiphilic macromolecule and uses thereof, and this amphiphilic macromolecule is applicable to oilfield drilling, well cementing, fracturing, crude oil gathering and transporting, sewage treating, sludge treating and papermaking, and it can be used as intensified oil producing agent and oil displacing agent, heavy oil viscosity reducer, fracturing fluid, clay stabilizer, sewage treating agent, retention aid and drainage aid and strengthening agent for papermaking.

BACKGROUND OF THE INVENTION

The main function of the polymer used for tertiary oil recovery is believed to increase solution viscosity and decrease water permeability in oil layer, so as to decrease mobility ratio and adjust water injection profile, and thus to enhance oil recovery by increasing the conformance factor. The solution viscosity and stability of the viscosity are important indicators for determining polymer displacement characteristics, and also are the key problem for determining recovery effect. With the continuous increase of oilfield comprehensive water content, it becomes increasingly difficult to extract oil and keep stable production, thus the requirements on the polymer used for tertiary oil recovery also increase constantly.

Heavy oil recovery is a common problem worldwide. The heavy oil has characteristics of high viscosity, high gum asphaltene content or high wax content; heavy oil gathers up about 70% sulfur and 90% nitrogen of the crude oil, the light component which accounts for about 70% of the total heavy oil is the convertible section by using the current technology, but it is still difficult to convert it efficiently. The heavy component which accounts for about 20% of the total heavy oil is difficult to be converted directly by using conventional technology. The rest of the heaviest is 10% of bottom residue of the heavy oil, which is rich in over 70% of metals and over 40% of sulfur and nitrogen, it can't be converted effectively into light product. The heavy oil does not easily flow in the formation, wellbore and oil pipeline. Furthermore, since the oil-water mobility ratio is big, heavy oil can easily cause many problems such as rapid water breakthrough, high water content of produced fluid, and easy formation sand production. The process for heavy oil recovery can be mainly divided into recovery of liquid flooding (e.g., hot water flooding, steam huff and puff, steam flood and so on) and recovery of yield enhancement (e.g., horizontal well, compositing branched well, electric heating and etc). A chemical viscosity reducer can disperse and emulsify the heavy oil effectively, reduce the viscosity of the heavy oil remarkably and decrease the flow resistance of heavy oil in the formation and wellbore, which is significantly important for reducing energy consumption in the process of recovery, decreasing discharging pollution and enhancing heavy oil recovery.

BRIEF DESCRIPTION OF THE INVENTION

In the following context of this invention, unless otherwise defined, the same variable group, and molecular and structural formula have the same definitions.

The instant invention relates to an amphiphilic macromolecule, this amphiphilic macromolecule has repeating units as described below: a structural unit A for adjusting molecular weight, molecular weight distribution and charge characteristics, a highly sterically hindered structural unit B and an amphiphilic structural unit C.

In an embodiment, the structural unit A for adjusting molecular weight, molecular weight distribution and charge characteristics comprises (meth)acrylamide monomer unit A₁ and/or (meth)acrylic monomer unit A₂. Preferably, the structural unit A includes (meth)acrylamide monomer unit A₁ and/or (meth)acrylic monomer unit A₂ simultaneously. In the art, the molecular weight of the amphiphilic macromolecule may be selected as needed, preferably, this molecular weight may be selected between 1000000-20000000.

Preferably, the (meth)acrylamide monomer unit A₁ has a structure of formula (1):

In formula (1), R₁ is H or a methyl group; R₂ and R₃ are independently selected from the group consisting of H and a C₁-C₃ alkyl group; R₂ and R₃ are preferably H.

Preferably, the (meth)acrylic monomer unit A₂ is (meth)acrylic acid and/or (meth)acrylate. Preferably the (meth)acrylate is sodium methacrylate.

Preferably, the molar percentage of (meth)acrylamide monomer unit A₁ in the entire amphiphilic macromolecule repeating units is 70-99 mol %; preferably 70-90 mol %, more preferably 72.85-78 mol %.

Preferably, the molar percentage of (meth)acrylic monomer unit A₂ in the entire amphiphilic polymer repeat units is 1-30 mol %; preferably 1-25 mol %, and more preferably 20-25 mol %.

In another embodiment, the structural unit A for the regulation of molecular weight, molecular weight distribution and charge characteristics has a structure of formula (2):

wherein, R₁ is H or a methyl group; R₂ and R₃ are independently selected from the group consisting of H and a C₁-C₃ alkyl group; R₂ and R₃ are preferably H; R₄ is selected from H or a methyl group; Gr is —OH or —O⁻Na⁺; m and n represent the molar percentages of the structural units in the entire amphiphilic macromolecule repeating units, and m is 70-99 mol %, preferably 70-90 mol %, more preferably 72.85-78 mol %; n is 1-30 mol %, preferably 1-25 mol %, more preferably 20-25 mol %.

In another embodiment, in formula (2), R₁-R₃ are preferably H, and Gr is preferably —O⁻Na⁺.

In another embodiment, the highly sterically hindered structural unit B contains at least a structure G, wherein the structure G is a cyclic hydrocarbon structure formed on the basis of two adjacent carbon atoms in the main chain, or is selected from a structure of formula (3), and the highly sterically hindered structural unit B optionally contains a structure of formula (4):

In formula (3), R₅ is H or a methyl group; preferably H; R₆ is a radical selected from the group consisting of the structures of formulas (5) and (6).

In formula (5), a is an integer from 1 to 11; preferably 1-7;

In formula (4), R₇ is H or a methyl group; R₈ is selected from the group consisting of —NHPhOH, —OCH₂Ph, —OPhOH, —OPhCOOH and salts thereof, —NHC(CH₃)₂CH₂SO₃H and salts thereof, —OC(CH₃)₂(CH₂)_(b)CH₃, —NHC(CH₃)₂(CH₂)_(c)CH₃, —OC(CH₃)₂CH₂C(CH₃)₂(CH₂)_(d)CH₃, —NHC(CH₃)₂CH₂C(CH₃)₂(CH₂)_(e)CH₃, —O(CH₂)_(f)N⁺(CH₃)₂CH₂PhX⁻,

wherein b and c are respectively integers from 0 to 21, preferably from 1 to 11; d and e are respectively integers from 0 to 17, preferably from 1 to 7; f is an integer from 2 to 8, preferably from 2 to 4; and X⁻ is CP or Br⁻.

Preferably, the highly sterically hindered structural unit B comprises a structure G and a structure of formula (4).

In another embodiment, the cyclic hydrocarbon structure formed on the basis of two adjacent carbon atoms in the main chain is selected from the group consisting of:

Preferably, the molar percentage of structure G of the highly sterically hindered structural unit B in the entire amphiphilic macromolecule repeating units is 0.02-2 mol %; preferably 0.02-1.0 mol %, more preferably 0.05-0.5 mol %.

Preferably, the molar percentage of the structure of formula (4) of the highly sterically hindered structural unit B in the entire amphiphilic macromolecule repeating units is 0.05-5 mol %; preferably 0.1-2.5 mol %, more preferably 0.1-1.0 mol %.

In another embodiment, the highly sterically hindered structural unit B has a structure of formula (7):

In formula (7), the definition on G is as described above, preferably the structure of formula (3),

the definitions on R₇ and R₈ are as described in formula (4). x and y represent the molar percentages of the structure units in the entire amphiphilic macromolecule repeating units, and x is 0.02-2 mol %, preferably 0.02-1.0 mol %, more preferably 0.05-0.5 mol %; y is 0.05-5 mol %, preferably 0.1-2.5 mol %, and more preferably 0.1-1.0 mol %.

In another embodiment, the amphiphilic structural unit C has a structure of formula (8):

In formula (8), R₉ is H or a methyl group; R₁₀ is —N⁺(CH₃)₂(CH₂)_(ξ)CH₃X⁻, —N⁺((CH₂)_(σ)CH₃)₃X⁻ or —N⁺(CH₃)((CH₂)_(τ)CH₃)₂X⁻; ξ is an integer from 3 to 21; σ is an integer from 2 to 9; τ is an integer from 3 to 15; X⁻ is Cl⁻ or Br⁻. Preferably, ξ is from 3 to 17, σ is from 2 to 5, τ is from 3 to 11.

Preferably, the molar percentage of amphiphilic structural unit C in the entire amphiphilic macromolecule repeating units is 0.05-10 mol %; preferably 0.1-5.0 mol %, more preferably 0.5-1.8 mol %.

In another embodiment, the amphiphilic macromolecule has a structure of formula (9):

In formula (9), the definitions on R₄, m and n are as described in formula (2); the definitions on R₇, R₈, G, x and y are as described in formula (7); the definitions on R₉ and R₁₀ are as described in formula (8); z represents the molar percentage of this structural unit in the entire amphiphilic macromolecule repeat units, and z is 0.05-10 mol %, preferably 0.1-5.0 mol %, more preferably 0.5-1.8 mol %.

Specifically, this present invention provides a high molecular compound having a structure of formulas (I)-(X):

The molecular weight of the amphiphilic macromolecule described above is between 1000000 and 20000000; preferably between 3000000 and 13000000.

The measurement of the molecular weight M is as follows: The intrinsic viscosity [η] is measured by Ubbelohde viscometer as known in the art, then the obtained intrinsic viscosity [η] value is used in the following equation to obtain the desired molecular weight M: M=802[η]^(1.25)

The amphiphilic macromolecule according to this present invention can be prepared by known methods in the art, for example, by polymerizing the structural unit for adjusting molecular weight, molecular weight distribution and charge characteristics, the highly sterically hindered structural unit and the amphiphilic structural unit in the presence of an initiator. The polymerization process can be any type well known in the art, such as, suspension polymerization, emulsion polymerization, solution polymerization, precipitation polymerization, and etc.

A typical preparation method is as follows: the above monomers are each dispersed or dissolved in an aqueous system under stirring, the monomer mixture is polymerized by the aid of an initiator under nitrogen atmosphere to form the amphiphilic macromolecule. The so far existing relevant technologies for preparing an amphiphilic macromolecule can all be used to prepare the amphiphilic macromolecule of this invention.

All the monomers for preparing the amphiphilic macromolecule can be commercially available, or can be prepared on the basis of prior art technology directly, and some monomers' synthesis are described in details in specific examples.

DESCRIPTION OF FIGURES

FIG. 1 depicts the relationship of viscosity vs. concentration of the amphiphilic macromolecules obtained from examples 1-5 of the invention in saline having a degree of mineralization of 3×10⁴ mg/L at a temperature of 85° C.

FIG. 2 depicts the relationship of viscosity vs. temperature of the amphiphilic macromolecules obtained from the examples 1-5 of the invention in saline having a degree of mineralization of 3×10⁴ mg/L at the concentration of 1750 mg/L.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is further illustrated below by combining specific examples; however, this invention is not limited to the following examples.

Example 1

This example synthesized the amphiphilic macromolecule of formula (I):

The synthesis of the amphiphilic macromolecule of this example was as follows:

Firstly, water, accounting for ¾ of the total weight of the reaction system, was charged into a reactor, then various monomers, totally accounting for ¼ of the total weight of the reaction system, were charged into the reactor as well, and the molar percentages m, n, x, y, z for each repeating units were 75%, 23%, 0.15%, 0.65%, 1.2% in succession. The mixture was stirred until complete dissolution, and a pH adjusting agent was then added in to adjust the reaction solution to have a pH value of about 9, then nitrogen gas was introduced in for 30 minutes to remove oxygen contained therein. An initiator was added into the reactor under the protection of nitrogen gas, and nitrogen gas was further continued for 10 minutes, then the reactor was sealed. The reaction was conducted at a temperature of 28° C.; after 5 hours, the reaction was ended with a complete conversion. After the drying of the obtained product, powdered amphiphilic macromolecule was obtained. The molecular weight of the amphiphilic macromolecule was 1160×10⁴.

Example 2

This example synthesized the amphiphilic macromolecule of formula (II).

The synthesis route of the monomer

was as follows:

The synthesis of the amphiphilic macromolecule of this example was as follows:

Firstly, water, accounting for ¾ of the total weight of the reaction system, was charged into a reactor, then various monomers, totally accounting for ¼ of the total weight of the reaction system, were charged into the reactor as well, and the molar percentages m, n, x, y, z for each repeating units were 75%, 24%, 0.15%, 0.1%, 0.75% in succession. The mixture was stirred until complete dissolution, and a pH adjusting agent was then added in to adjust the reaction solution to have a pH value of about 8, then nitrogen gas was introduced in for 40 minutes to remove oxygen contained therein. An initiator was added into the reactor under the protection of nitrogen gas, and nitrogen gas was further continued for 10 minutes, then the reactor was sealed. The reaction was conducted at a temperature of 25° C.; after 5.5 hours, the reaction was ended with a complete conversion. After the drying of the obtained product, powdered amphiphilic macromolecule was obtained. The molecular weight of the amphiphilic macromolecule was 730×10⁴.

Example 3

This example synthesized the amphiphilic macromolecule of formula (III):

The synthesis route of the monomer

was as follows:

The synthesis of the amphiphilic macromolecule of this example was as follows:

Firstly, water, accounting for ¾ of the total weight of the reaction system, was charged into a reactor, then various monomers, totally accounting for ¼ of the total weight of the reaction system, were charged into the reactor as well, and the molar percentages m, n, x, y, z for each repeating units were 77%, 21%, 0.25%, 0.25%, 1.5% in succession. The mixture was stirred until complete dissolution, and a pH adjusting agent was then added in to adjust the reaction solution to have a pH value of about 9, then nitrogen gas was introduced in for 30 minutes to remove oxygen contained therein. An initiator was added into the reactor under the protection of nitrogen gas, and nitrogen gas was further continued for 10 minutes, then the reactor was sealed. The reaction was conducted at a temperature of 23° C.; after 5 hours, the reaction was ended with a complete conversion. After the drying of the obtained product, powdered amphiphilic macromolecule was obtained. The molecular weight of the amphiphilic macromolecule was 720×10⁴.

Example 4

This example synthesized the amphiphilic macromolecule of formula (IV):

The synthesis route of the monomer

was as follows:

The synthesis of the amphiphilic macromolecule of this example was as follows:

Firstly, water, accounting for ¾ of the total weight of the reaction system, was charged into a reactor, then various monomers, totally accounting for ¼ of the total weight of the reaction system, were charged into the reactor as well, and the molar percentages m, n, x, y, z for each repeating units were 75%, 23%, 0.05%, 0.15%, 1.8% in succession. The mixture was stirred until complete dissolution, and a pH adjusting agent was then added in to adjust the reaction solution to have a pH value of about 9, then nitrogen gas was introduced in for 30 minutes to remove oxygen contained therein. An initiator was added into the reactor under the protection of nitrogen gas, and nitrogen gas was further continued for 10 minutes, then the reactor was sealed. The reaction was conducted at a temperature of 28° C.; after 5 hours, the reaction was ended with a complete conversion. After the drying of the obtained product, powdered amphiphilic macromolecule was obtained. The molecular weight of the amphiphilic macromolecule was 460×10⁴.

Example 5

This example synthesized the amphiphilic macromolecule of formula (V):

The synthesis route of the monomer

was as follows

The synthesis of the amphiphilic macromolecule of this example was as follows:

Firstly, water, accounting for ¾ of the total weight of the reaction system, was charged into a reactor, then various monomers, totally accounting for ¼ of the total weight of the reaction system, were charged into the reactor as well, and the molar percentages m, n, x, y, z for each repeating units were 78%, 20%, 0.2%, 1%, 0.8% in succession. The mixture was stirred until complete dissolution, and a pH adjusting agent was then added in to adjust the reaction solution to have a pH value of about 10, then nitrogen gas was introduced in for 30 minutes to remove oxygen contained therein. An initiator was added into the reactor under the protection of nitrogen gas, and nitrogen gas was further continued for 10 minutes, then the reactor was sealed. The reaction was conducted at a temperature of 25° C.; after 6 hours, the reaction was ended with a complete conversion. After the drying of the obtained product, powdered amphiphilic macromolecule was obtained. The molecular weight of the amphiphilic macromolecule was 580×10⁴.

Example 6

This example synthesized the amphiphilic macromolecule of formula (VI):

The synthesis of the amphiphilic macromolecule of this example was as follows:

Firstly, water, accounting for ¾ of the total weight of the reaction system, was charged into a reactor, then various monomers, totally accounting for ¼ of the total weight of the reaction system, were charged into the reactor as well, and the molar percentages m, n, x, y, z for each repeating units were 73%, 24%, 0.5%, 1%, 1.5% in succession. The mixture was stirred until complete dissolution, and a pH adjusting agent was then added in to adjust the reaction solution to have a pH value of about 8, then nitrogen gas was introduced in for 30 minutes to remove oxygen contained therein. An initiator was added into the reactor under the protection of nitrogen gas, and nitrogen gas was further continued for 10 minutes, then the reactor was sealed. The reaction was conducted at a temperature of 55° C.; after 3 hours, the reaction was ended with a complete conversion. After the drying of the obtained product, powdered amphiphilic macromolecule was obtained. The molecular weight of the amphiphilic macromolecule was 770×10⁴.

Example 7

This example synthesized the amphiphilic macromolecule of formula (VII):

The synthesis of the amphiphilic macromolecule of this example was as follows:

Firstly, water, accounting for ¾ of the total weight of the reaction system, was charged into a reactor, then various monomers, totally accounting for ¼ of the total weight of the reaction system, were charged into the reactor as well, and the molar percentages m, n, x, y, z for each repeating units were 77%, 22%, 0.25%, 0.25%, 0.5% in succession. The mixture was stirred until complete dissolution, and a pH adjusting agent was then added in to adjust the reaction solution to have a pH value of about 9, then nitrogen gas was introduced in for 30 minutes to remove oxygen contained therein. An initiator was added into the reactor under the protection of nitrogen gas, and nitrogen gas was further continued for 10 minutes, then the reactor was sealed. The reaction was conducted at a temperature of 55° C.; after 2 hours, the reaction was ended with a complete conversion. After the drying of the obtained product, powdered amphiphilic macromolecule was obtained. The molecular weight of the amphiphilic macromolecule was 920×10⁴.

Example 8

This example synthesized the amphiphilic macromolecule of formula (VIII):

The synthesis of the amphiphilic macromolecule of this example was as follows:

Firstly, water, accounting for ¾ of the total weight of the reaction system, was charged into a reactor, then various monomers, totally accounting for ¼ of the total weight of the reaction system, were charged into the reactor as well, and the molar percentages m, n, x, y, z for each repeating units were 72.85%, 25%, 0.15%, 1%, 1% in succession. The mixture was stirred until complete dissolution, and a pH adjusting agent was then added in to adjust the reaction solution to have a pH value of about 10, then nitrogen gas was introduced in for 30 minutes to remove oxygen contained therein. An initiator was added into the reactor under the protection of nitrogen gas, and nitrogen gas was further continued for 10 minutes, then the reactor was sealed. The reaction was conducted at a temperature of 55° C.; after 3 hours, the reaction was ended with a complete conversion. After the drying of the obtained product, powdered amphiphilic macromolecule was obtained. The molecular weight of the amphiphilic macromolecule was 430×10⁴.

Example 9

This example synthesized the amphiphilic macromolecule of formula (IX):

The synthesis of the amphiphilic macromolecule of this example was as follows:

Firstly, water, accounting for ¾ of the total weight of the reaction system, was charged into a reactor, then various monomers, totally accounting for ¼ of the total weight of the reaction system, were charged into the reactor as well, and the molar percentages m, n, x, y, z for each repeating units were 75%, 23%, 0.25%, 0.25%, 1.5% in succession. The mixture was stirred until complete dissolution, and a pH adjusting agent was then added in to adjust the reaction solution to have a pH value of about 8, then nitrogen gas was introduced in for 30 minutes to remove oxygen contained therein. An initiator was added into the reactor under the protection of nitrogen gas, and nitrogen gas was further continued for 10 minutes, then the reactor was sealed. The reaction was conducted at a temperature of 50° C.; after 2.5 hours, the reaction was ended with a complete conversion. After the drying of the obtained product, powdered amphiphilic macromolecule was obtained. The molecular weight of the amphiphilic macromolecule was 690×10⁴.

Example 10

This example synthesized the amphiphilic macromolecule of formula (X):

The synthesis of the amphiphilic macromolecule of this example was as follows:

Firstly, water, accounting for ¾ of the total weight of the reaction system, was charged into a reactor, then various monomers, totally accounting for ¼ of the total weight of the reaction system, were charged into the reactor as well, and the molar percentages m, n, x, y, z for each repeating units were 75%, 23%, 0.25%, 0.25%, 1.5% in succession. The mixture was stirred until complete dissolution, and a pH adjusting agent was then added in to adjust the reaction solution to have a pH value of about 8, then nitrogen gas was introduced in for 30 minutes to remove oxygen contained therein. An initiator was added into the reactor under the protection of nitrogen gas, and nitrogen gas was further continued for 10 minutes, then the reactor was sealed. The reaction was conducted at a temperature of 50° C.; after 4 hours, the reaction was ended with a complete conversion. After the drying of the obtained product, powdered amphiphilic macromolecule was obtained. The molecular weight of the amphiphilic macromolecule was 830×10⁴.

MEASUREMENT EXAMPLES Measurement Example 1

Saline having a mineralization degree of 3×10⁴ mg/L was used to prepare amphiphilic macromolecule solutions with different concentrations, and the relationship between the concentration, temperature and the viscosity of the solution was determined. The results were shown in FIG. 1 and FIG. 2.

The figures showed that the amphiphilic macromolecule solutions of examples 1-5 still have favorable viscosifying capacity under the condition of high temperature and high degree of mineralization. The highly sterically hindered unit in the amphiphilic macromolecule reduced the rotational degree of freedom in the main chain and increased the rigidity of the macromolecule chain, which made the macromolecule chain difficult to curl and tend to stretch out, thus enlarging the hydrodynamic radius of the macromolecule; in the meantime, the amphiphilic structural unit associated each other to form the microdomain by intramolecular- or intermolecular-interaction, thus enhancing the viscosifying capacity of the solution remarkably under the conditions of high temperature and high salinity.

Measurement Example 2

Testing method: Under a testing temperature of 25° C., 25 ml electric dehydration crude oil samples from three types of oilfields were added in a 50 ml test tube with a plug, then 25 ml aqueous solutions of amphiphilic macromolecule with different concentrations formulated with distilled water were added in. The plug of the test tube was tightened, then the test tube was shaken manually or by using an oscillating box for 80-100 times in horizontal direction, and the shaking amplitude should be greater than 20 cm. After sufficient mixing, the plug of the test tube was loosed. Viscosity reduction rate for crude oil was calculated according to the following equation:

${{Viscosity}\mspace{14mu}{reduction}\mspace{14mu}{{rate}(\%)}} = {\frac{{{viscosity}\mspace{14mu}{of}\mspace{14mu}{crude}\mspace{14mu}{oil}\mspace{14mu}{sample}} - {{viscosity}\mspace{14mu}{after}\mspace{14mu}{mixing}}}{{viscosity}\mspace{14mu}{of}\mspace{14mu}{crude}\mspace{14mu}{oil}\mspace{14mu}{sample}} \times 100}$

TABLE 1 Experimental results of the heavy oil viscosity reduction of the amphiphilic macromolecule obtained from the example 6 to example 10 (oil-water ratio 1:1, 25) oil-water volume ratio (1:1) oil viscosity oil viscosity oil viscosity test temperature sample reduction sample reduction sample reduction (25° C.) 1 rate(%) 2 rate(%) 3 rate(%) initial viscosity (mPa · s) 1650 — 5100 — 16000 — Example 6 400 mg/L 730 55.76 1750 65.69 7100 55.63 600 mg/L 470 71.52 1250 75.49 3250 79.69 800 mg/L 330 80.00 950 81.37 1850 88.44 1000 mg/L  295 82.12 820 83.92 1500 90.63 1200 mg/L  270 83.64 675 86.76 1225 92.34 Example 7 400 mg/L 780 52.73 1800 64.71 7700 51.88 600 mg/L 590 64.24 1350 73.53 4200 73.75 800 mg/L 460 72.12 1100 78.43 2850 82.19 1000 mg/L  340 79.39 880 82.75 1900 88.13 1200 mg/L  300 81.82 790 84.51 1500 90.63 Example 8 400 mg/L 820 50.30 1475 71.08 5650 64.69 600 mg/L 590 64.24 1200 76.47 3950 75.31 800 mg/L 450 72.73 850 83.33 2600 83.75 1000 mg/L  375 77.27 670 86.86 1450 90.94 1200 mg/L  330 80.00 620 87.84 1290 91.94 Example 9 400 mg/L 780 52.73 1450 71.57 5800 63.75 600 mg/L 450 72.73 1150 77.45 4100 74.38 800 mg/L 360 78.18 850 83.33 2500 84.38 1000 mg/L  280 83.03 680 86.67 1570 90.19 1200 mg/L  260 84.24 620 87.84 1390 91.31 Example 10 400 mg/L 710 56.97 1450 71.57 5270 67.06 600 mg/L 500 69.70 1050 79.41 3100 80.63 800 mg/L 410 75.15 830 83.73 1890 88.19 1000 mg/L  320 80.61 675 86.76 1200 92.50 1200 mg/L  270 83.64 650 87.25 950 94.06

Table 1 showed that the amphiphilic macromolecules of examples 6-10 had good effects for viscosity reduction as to all three oil samples. With the increase of the concentration of the amphiphilic macromolecule solution, the viscosity reduction rate increased. And, when the concentration of the amphiphilic macromolecule solution was the same, the viscosity reduction rate increased with the enhancing of the viscosity of the oil sample. It was believed that the amphiphilic macromolecule could reduce the viscosity of the crude oil remarkably via a synergetic effect between the highly sterically hindered structural unit and the amphiphilic structural unit, which could emulsify and disperse the crude oil effectively.

INDUSTRIAL APPLICATION

The amphiphilic macromolecule of this invention can be used in oilfield drilling, well cementing, fracturing, crude oil gathering and transporting, sewage treating, sludge treating and papermaking, and it can be used as intensified oil producing agent and oil displacing agent, heavy oil viscosity reducer, fracturing fluid, clay stabilizer, sewage treating agent, retention aid and drainage aid and strengthening agent for papermaking.

The amphiphilic macromolecule of this invention is especially suitable for crude oil exploitation, for instance, it can be used as an intensified oil displacement polymer and a viscosity reducer for heavy oil. When it is used as an oil displacement agent, it has remarkable viscosifying effect even under the condition of high temperature and high salinity, and can thus enhance the crude oil recovery. When it is used as a viscosity reducer for heavy oil, it can remarkably reduce the viscosity of the heavy oil and decrease the flow resistance thereof in the formation and wellbore by emulsifying and dispersing the heavy oil effectively. 

What is claimed is:
 1. An amphiphilic macromolecule comprising: as repeating units, a structural unit A for adjusting molecular weight, molecular weight distribution and charge characteristics, a sterically hindered structural unit B and an amphiphilic structural unit C, wherein the amphiphilic structural unit C has a structure of formula (8):

wherein in formula (8), R₉ is H or a methyl group; R₁₀ is —N⁺(CH₃)₂(CH₂)₈₆CH₃X⁻, —N⁺((CH₂)_(σ)CH₃)₃X⁻ or —N⁺(CH₃)((CH₂)_(τ)CH₃)₂X⁻; ξ is an integer from 3 to 21; σ is an integer from 2 to 9; τ is an integer from 3 to 15; and X⁻ is Cl⁻ or Br⁻; and wherein the structural unit A for adjusting the molecular weight, molecular weight distribution and charge characteristics comprises a (meth)acrylamide monomer unit A₁ and a (meth)acrylic monomer unit A₂; and wherein the sterically hindered structural unit B contains a structure G, the structure G is a cyclic hydrocarbon structure formed on the basis of two adjacent carbon atoms in the main chain, or is selected from a structure of formula (3), and the sterically hindered structural unit B optionally contains a structure of formula (4):

wherein in formula (3), R₅ is H or a methyl group; R₆ is a radical selected from the structures of formula (5) and formula (6),

wherein in formula (5), a is an integer from 1 to 11, and wherein in formula (4), R₇ is H or a methyl group; R₈ is selected from the group consisting of —NHPhOH, —OCH₂Ph, —OPhOH, —OPhCOOH and salts thereof, —NHC(CH₃)₂CH₂SO₃H and salts thereof, —OC(CH₃)₂(CH₂)_(b)CH₃, —NHC(CH₃)₂(CH₂)_(c)CH₃, —OC(CH₃)₂CH₂C(CH₃)₂(CH₂)_(d)CH₃, —NHC(CH₃)₂CH₂C(CH₃)₂(CH₂)_(e)CH₃, —O(CH₂)_(f)N⁺(CH₃)₂CH₂PhX⁻,

wherein b and c are integers from 0 to 21 respectively; d and e are integers from 0 to 17 respectively; f is an integer from 2 to 8; and X⁻ is Cl⁻ or Br.
 2. The amphiphilic macromolecule as claimed in claim 1, wherein based on 100 mol % of the entire amphiphilic macromolecule repeating units, the molar percentage of the (meth)acrylamide monomer unit A₁ is 70-99 mol %; and the molar percentage of the (meth)acrylic monomer unit A₂ is 1-30 mol %.
 3. The amphiphilic macromolecule as claimed in claim 1, wherein based on 100 mol % of the entire amphiphilic macromolecule repeating units, the molar percentage of the structure G is 0.02-2 mol %; and the molar percentage of the structure of formula (4) is 0.05-5 mol %.
 4. The amphiphilic macromolecule as claimed in claim 1, wherein based on 100 mol % of the entire amphiphilic macromolecule repeating units, the molar percentage of the structure of formula (8) is 0.05-10 mol %.
 5. The amphiphilic macromolecule as claimed in claim 1, wherein the cyclic hydrocarbon structure formed on the basis of the two adjacent carbon atoms in the main chain is selected from the group consisting of:


6. The amphiphilic macromolecule as claimed in claim 1, wherein the sterically hindered structural unit B has a structure of formula (7):

wherein in formula (7) the definition on R7 and R₈ are as described in formula (4); x and y respectively represent the molar percentages of the structural units in the entire amphiphilic macromolecule, and x is from 0.02 to 2 mol %, y is from 0.05 to 5 mol %.
 7. The amphiphilic macromolecule as claimed in claim 1, wherein the amphiphilic macromolecule has a structure of formula (9):

in formula (9), the definitions on R₄, m and n are as described in formula (2); the definitions on R₇, R₈, G, x and y are as described in formula (7); the definitions on R₉ and R₁₀ are as described in formula (8); z represents the molar percentage of this structural unit in the entire amphiphilic macromolecule repeating unit, and z is from 0.05 to 10 mol %.
 8. The amphiphilic macromolecule as claimed in claim 1, which is a compound of formulas (I)-(X):

wherein m, n, x, y, and z in formulae (I) to (X) respectively represent the molar percentages of the structural units in the entire amphiphilic macromolecule, in which, m is from 70 to 99 mol %; n is from 1 to 30 mol %; x is from 0.02 to 2 mol %, y is from 0.05 to 5 mol %, and z is from 0.05 to 10 mol %.
 9. The amphiphilic macromolecule as claimed in claim 1, wherein the amphiphilic macromolecule has a molecular weight of between 1000000-20000000.
 10. A method comprising: formulating the amphiphilic macromolecule as claimed in claim 1 into an aqueous solution; and utilizing the aqueous solution in oilfield drilling, well cementing, fracturing, crude oil gathering and transporting, sewage treating, sludge treating and papermaking as intensified oil producing agent and oil displacing agent, or as a heavy oil viscosity reducer, fracturing fluid component, clay stabilizer, sewage treating agent, retention aid and drainage aid or strengthening agent for papermaking.
 11. An amphiphilic macromolecule comprising: as repeating units, a structural unit A for adjusting molecular weight, molecular weight distribution and charge characteristics, a sterically hindered structural unit B and an amphiphilic structural unit C, wherein the amphiphilic structural unit C has a structure of formula (8):

wherein in formula (8), R₉ is H or a methyl group; R₁₀ is —N⁺(CH₃)₂(CH₂)_(ξ)CH₃X⁻, —N⁺((CH₂)_(σ)CH₃)₃X⁻ or —N⁺(CH₃)((CH₂)_(τ)CH₃)₂X⁻; ξ is an integer from 3 to 21; σ is an integer from 2 to 9; τ is an integer from 3 to 15; and X⁻ is Cl⁻ or Br⁻; and wherein the structural unit A for adjusting molecular weight, molecular weight distribution and charge characteristics has a structure of formula (2);

wherein in formula (2), R₁ is H or a methyl group; R₂ and R₃ are independently selected from the group consisting of H and a C₁-C₃ alkyl group; R₄ is selected from the group consisting of H and a methyl group; Gr is —OH or —O⁻Na⁺; m and n represent the molar percentages of the structural units in the entire amphiphilic macromolecule, and m is from 70 to 99 mol %; n is from 1 to 30 mol %. 